A conventional brake lever for a heavy road vehicle is mounted on an S-cam shaft of a drum brake and is connected to a brake cylinder, as is well known in the art. It contains an automatic slack adjuster, which for its function needs a control signal, provided by a control arm connected to a fix-point on the vehicle, normally by means of an anchor bracket.
Conventionally, the control arm and the anchor bracket are connected by means of a screw-Joint, containing a washer and possibly a wear-reducing plastic insert. At mounting the corresponding holes in the two parts have to be aligned and the screw-joint (screw and nut) securely fastened. Due to vibrations and mutual movements it is difficult to obviate wear and noise. The screw-joint may also give difficulties at later dismounting.
Another possibility is to provide the anchor bracket with a slot for cooperation with a suitably shaped end of the control arm. The cooperating contact surfaces are small, which means that the problem with wear is not obviated, even if the mounting difficulties are decreased.